I use a mix. Sometimes, I'll read stuff in the foliate app on Linux from my desktop outputting onto a big screen tv.
But I also do an old kindle while lounging on couch/bed and Librera reader on phone (android/f-droid) when I'm on the shitter.
For the most part, I load different things on each and just jump back and forth between several stories. Keeps things interesting and no need to sync bookmarks and whatnot.
probably just people who don't want to bother with compiling everything would be my guess